Cell-Sized Confinements Alter Molecular Diffusion in Concentrated Polymer Solutions Due to Length-Dependent Wetting of Polymers

ACS Materials Au, Journal Year: 2023, Volume and Issue: 3(5), P. 442 - 449

Published: May 16, 2023

Living cells are characterized by the micrometric confinement of various macromolecules at high concentrations. Using droplets containing binary polymer blends as artificial cells, we previously showed that cell-sized causes phase separation solutions because length-dependent wetting polymers. Here, demonstrate confinement-induced heterogeneity polymers also emerges in single-component solutions. The resulting structural leads to a slower transport small molecules center than bulk Coarse-grained molecular simulations support this heterogeneous distribution length and effective shorter chains droplet surface originates from conformational entropy. Our results suggest functions regulator for polydisperse specifically manipulates diffusion molecules, particularly those with sizes close correlation chains.

Language: Английский

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Generalized time-fractional kinetic-type equations with multiple parameters

Chaos An Interdisciplinary Journal of Nonlinear Science, Journal Year: 2025, Volume and Issue: 35(2)

Published: Feb. 1, 2025

In this paper, we study a new generalization of the kinetic equation emerging in run-and-tumble models [see, e.g., Angelani et al., J. Stat. Phys. 191, 129 (2024) for time-fractional version equation]. We show that leads to wide class generalized fractional (GFK) and telegraph-type equations depend on two (or three) parameters. provide an explicit expression solution Laplace domain that, particular choice parameters, fundamental GFK can be interpreted as probability density function stochastic process obtained by suitable transformation inverse subordinator. Then, discuss some particularly interesting cases, such telegraph models, diffusion involving higher order time derivatives, integral equations.

Language: Английский

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Two-dimensional Brownian motion with dependent components: Turning angle analysis

Chaos An Interdisciplinary Journal of Nonlinear Science, Journal Year: 2025, Volume and Issue: 35(2)

Published: Feb. 1, 2025

Brownian motion in one or more dimensions is extensively used as a stochastic process to model natural and engineering signals, well financial data. Most works dealing with multidimensional consider the different independent components. In this article, we investigate of correlated R2, where individual components are not necessarily independent. We explore various statistical properties under consideration, going beyond conventional analysis second moment. Our particular focus lies on investigating distribution turning angles. This reveals particularly interesting characteristics for processes dependent that relevant applications diverse physical systems. Theoretical considerations supported by numerical simulations two real-world datasets: data Dow Jones Industrial Average Standard Poor’s 500, trajectories polystyrene beads water. Finally, show can be readily extended correlations change over time.

Language: Английский

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Quasi‐Diffusion Imaging: Application to Ultra‐High b‐Value and Time‐Dependent Diffusion Images of Brain Tissue

NMR in Biomedicine, Journal Year: 2025, Volume and Issue: 38(4)

Published: Feb. 28, 2025

ABSTRACT We demonstrate that quasi‐diffusion imaging (QDI) is a signal representation extends towards the negative power law regime. evaluate QDI for in vivo human and ex fixed rat brain tissue across ‐value ranges from 0 to 25,000 s mm −2 , determine whether accurate parameter estimates can be acquired clinically feasible scan times investigate their diffusion time‐dependence. Several mathematical properties of are presented. describes magnetic resonance (dMRI) attenuation by two fitting parameters within Mittag–Leffler function (MLF). present its asymptotic at low high ‐values define inflection point (IP) above which tends law. To show provides an dMRI signal, we apply it datasets (Dataset 1: ; Dataset 2: ) 3: ms). A 4 subset 1 ( also analysed (acquisition time 6 min 16 s). showed excellent fits observed attenuation, identified IPs provided apparent Stable were upon increasing maximum range near IPs, suggesting valid large with multiple times. accurately estimated shorter data acquisition, time‐dependence was approaching Gaussian tortuosity limit time. In conclusion, parsimonious sensitive microstructural heterogeneity cell membrane permeability.

Language: Английский

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Machine learning analysis of anomalous diffusion

The European Physical Journal Plus, Journal Year: 2025, Volume and Issue: 140(3)

Published: March 2, 2025

Language: Английский

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